瑞金新知速递 第742期|王卫庆教授探究口罩引起的心肺负担

2023年6月，王卫庆教授在《JAMA Network Open》杂志发表题名为“Evaluation of Mask-Induced Cardiopulmonary Stress: A Randomized Crossover Trial.”——探究口罩引起的心肺负担：一项随机交叉临床试验的研究论文。

瑞金医院内分泌学科王卫庆教授、潘诗佳研究员为论文的共同通讯作者；包日强医师为论文的第一作者。

doi: 10.1001/jamanetworkopen.2023.17023.

在新冠时代结束之后，人们开始重新审视口罩的作用——口罩到底是“百利无一害”还是“一把双刃剑”呢？该研究采用自身交叉对照研究设计，利用代谢舱平台首次精准的监测并探究了佩戴N95口罩对于人体的影响。研究发现长时间佩戴N95口罩之后，参与者的呼吸阻力会有所增加，血氧和pH也会随之降低，进而导致交感神经系统的激活以及肾上腺素、去甲肾上腺素的分泌增加，激素的改变提高了心率和血压以及能量消耗，最终导致心肺负荷增加。并且这种心肺负荷在运动时进一步增强。

该研究表明长时间佩戴N95口罩会显著影响人体生理、生化指标和主观感受，带来一定程度的心肺负荷。虽然健康人可以代偿这种心肺负荷，但其他代偿能力受损的人群，如老年人、儿童和患有心肺疾病的人，需要警惕佩戴口罩可能的危害。

【Abstract】

Introduction: Face masks have been proven effective in reducing the transmission of   COVID-19. As airborne diseases continue to emerge, mask use is still   suggested in public and work spaces as a precautionary measure. In China,   mask use remains a highly adopted practice in everyday life. However, studies   on the adverse effects of wearing masks yielded inconsistent conclusions due   to short duration of intervention. Given that the N95 mask offers the highest   level of protection against viruses such as COVID-19, we systematically   evaluated the effects of extended use of the N95 mask.

Methods: This randomized clinical trial included 30 healthy participants. The   study was conducted in a metabolic chamber to strictly control daily calorie   intake and physical activity levels. With the use of stratified   randomization, participants were randomly assigned to receive interventions   with and without the N95 mask for 14 hours (8:00 to 22:00), during which they   exercised for 30 minutes in the morning and afternoon using an ergometer at 40%   (light intensity) and 20% (very light intensity) of their maximum oxygen   consumption levels, respectively. Venous blood samples were taken before and   14 hours after the intervention for blood gas and metabolite analysis. Differences   were estimated using a linear mixed-effects model. Where significant, Bonferroni-corrected   post hoc tests were performed.

Results: Thirty randomized participants (mean [SD] age, 26.1 [2.9] years; 15   women [50%]) completed the study. Wearing the N95 mask resulted in reduced   respiration rate and oxygen saturation by pulse oximetry (SpO2) within 1   hour, with elevated heart rate (mean change, 3.8 beats/min [95% CI, 2.6-5.1 beats/min])   2 hours later until mask off at 22:00. During the light-intensity exercise at   11:00, mask-induced cardiopulmonary stress was further increased, as heart   rate (mean change, 7.8 beats/min [95% CI, 5.3-10.2 beats/min]) and blood   pressure (systolic: mean change, 6.1 mm Hg [95% CI, 0.6-11.5 mm Hg];   diastolic: mean change, 5.0 mm Hg [95% CI, 0.3-9.6 mm Hg]) increased, while   respiration rate (mean change, −4.3 breaths/min [95% CI, −6.4 to 2.3   breaths/min]) and SpO2 (mean change, −0.66% [95% CI, −1.0% to 0.3%])   decreased. Energy expenditure (mean change, 0.5 kJ [95% CI, 0.2-0.8] kJ) and   fat oxidation (mean change, 0.01 g/min [95% CI, −0.01 to 0.03 g/min]) were elevated   at 11:00. After the 14-hour masked intervention, venous blood pH decreased,   and calculated arterial pH showed a decreasing trend. Metanephrine and   normetanephrine levels were increased. Participants also reported increased   overall discomfort with the N95 mask.

Discussion: The findings contribute to existing literature by demonstrating that   wearing the N95 mask for 14 hours significantly affected the physiological,   biochemical, and perception parameters. The effect was primarily initiated by   increased respiratory resistance and subsequent decreased blood oxygen and   pH, which contributed to sympathoadrenal system activation and epinephrine as   well as norepinephrine secretion elevation. The extra hormones elicited a   compensatory increase in heart rate and blood pressure. Although healthy   individuals can compensate for this cardiopulmonary overload, other   populations, such as elderly individuals, children, and those with   cardiopulmonary diseases, may experience compromised compensation. Chronic   cardiopulmonary stress may also increase cardiovascular diseases and overall   mortality. 6 However, the study was limited to only 30 young healthy   participants in a laboratory setting; further investigation is needed to   explore the effects of different masks on various populations in clinical   settings. 

【中文摘要】

背景：口罩已被证明在减少COVID-19的传播方面有效。由于空气传播的疾病继续出现，口罩仍然被建议作为公共和工作场所的预防措施。在中国，口罩在日常生活中使用频率依然很高。然而，由于既往研究干预持续时间较短，关于佩戴口罩的不良影响的尚无统一定论。在该研究中，研究者系统评估了长时间佩戴N95口罩的影响。

方法：该随机临床试包括30名健康参与者。整个研究在代谢舱中进行，同时严格控制每日卡路里摄入量和体力活动水平。通过分层随机化，参与者被随机分配到佩戴和不佩戴N95口罩的干预组和对照组，干预持续14小时（8:00至22:00），期间分别使用功率计以40%（轻度）和20%（极轻度）的最大氧耗水平进行30分钟的运动。在干预前和14小时后，采集静脉血样进行血气和代谢物分析。差异使用线性混合效应模型进行估计。在显著性水平下进行Bonferroni校正的事后检验。

结果：30名随机参与者（Mean [SD]年龄为26.1 [2.9]岁；女性15名[50%]）完成了研究。佩戴N95口罩导致呼吸频率和脉搏血氧饱和度在1小时内发生降低，2小时后心率升高（平均变化3.8次/分钟[95%CI，2.6-5.1次/分钟]），直至22:00摘下口罩。在11:00进行轻度运动时，口罩引起的心肺压力进一步增加，心率（平均变化7.8次/分钟[95%CI，5.3-10.2次/分钟]）和血压（收缩压：平均变化6.1 mm Hg [95%CI，0.6-11.5 mm Hg]；舒张压：平均变化5.0 mm Hg [95%CI，0.3-9.6 mm Hg]）进一步增加，而呼吸频率（平均变化-4.3次/分钟[95%CI，-6.4到2.3次/分钟]）和SpO2（平均变化-0.66%[95%CI，-1.0%到0.3%]）降低。同时能量消耗（平均变化0.5 kJ[95%CI，0.2-0.8 kJ]）和脂肪氧化（平均变化0.01 g/min[95%CI，-0.01到0.03 g/min]）也增加。在进行14小时佩戴口罩干预后，静脉血pH降低，计算得出的动脉pH呈下降趋势。甲肾上腺素和去甲肾上腺素水平增加。参与者还表示佩戴N95口罩时的整体不适感增加。

讨论：研究结果表明佩戴N95口罩显著影响生理、生化和感知参数。该影响主要是由呼吸阻力增加和进一步的血氧及pH降低引起的，这促使交感-肾上腺系统激活，肾上腺素与去甲肾上腺素分泌升高。额外的激素引起了心率和血压的代偿性增加。尽管健康个体可以代偿这种心肺负荷，但其他人群，如老年人、儿童和心肺疾病患者，可能存在代偿能力受损的情况。而且慢性心肺负荷也可能增加心血管疾病和总体死亡率。然而该研究仅限于在实验室环境中的30名年轻健康参与者；需要进一步研究来探索不同口罩对不同人群在不同环境中的影响。 

作者简介

王卫庆   教授，主任医师，上海交通大学医学院附属瑞金医院内分泌代谢科主任，上海市内分泌代谢病研究所副所长；研究方向：内分泌代谢性疾病的基础与临床研究。

潘诗佳  研究员，上海交通大学附属瑞金医院/上海市内分泌代谢病研究所；研究方向：人体能量代谢平衡监测及能量稳态失衡相关疾病的探究。

包日强   医师，上海交通大学医学院附属瑞金医院/上海市内分泌代谢病研究所；研究方向：人体能量代谢平衡监测及能量稳态失衡相关疾病的探究。

Evaluation of Mask-Induced Cardiopulmonary Stress A Randomized Crossover Trial.pdf